已知x,y,z∈R+.求证(1+x2)(1+y2)(1+z2)≥8xyz
已知x,y,z∈R,且x+y+z=1,x2+y2+z2=3,则xyz的最大值是______.
已知xyz=1,x+y+z=2,x2+y2+z2=16,求1/x+y+1/y+z+1/x+z
x,y,z为正实数 求证 x2/(y2+z2+yz)+y2/(z2+x2+zx)+z2/(x2+y2+xy)>=1
已知xyz=1,x+y+z=2,x2+y2+z2=16,求代数式1xy+2z+1yz+2x+1zx+2y
已知X,Y,Z是实数,且X2+Y2+Z2=3,X+Y+Z=1,则XYZ最大值是
已知x,y,z互不相等,且xyz不等于0,x2+yz=z2,y2+zx=x2,求证:z2+xy=y2
一道不等式的证明题,已知:(x2-1)(y2-1)(z2-1)=83 x,y,z>1求证:1/x+1/y+1/z≥1
已知xyz=1.x2+y2+z2=16.求1/xy+2z+1/yz+2x+1/xz+2y的值
已知x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求代数式x2/(y+z)+y2/(x+z)+z2/
已知实数x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求x2/(y+z)+y2/(z+x)+z2/(
已知x.y∈R,求证x2+y2+1≥x+y+xy
求方程xyz + x2 + y2 + z2 = 2 确定的函数z = z( x,y)在点(1,0,-1)处的全微分dz,